What type of food do you feed them? I know that the ash content is very important for males - although I can't remember if it is high ash or low ash - sorry. But it looks like you do have a problem.

I know you now this, but sometimes repeating it will help, so here goes (don't get mad, I'm just trying to help!):

Cats do NOT like change in their lives, sounds like Allen has had a lot of change recently. Go back to feeding him first, and where he likes to be fed. Have you moved his favorite bed? The scratching post, did you move that? How about his litter box?

You said he had to share a room with your son, did he enjoy doing that? Now that your son is gone, maybe Allen can have "his" room back - give him a few days to get reaquianted with that. Are the other kitties picking on him? If so, why??

Are they drinking enough? Maybe adding wet food with water - mix it like a soup will give him more water in his diet.

You have to play pet dectective and find out what is bugging them. If you think it is UTI, then go to the vet (I know you already have an appointment) Antibiotics will help with the UTI, but not if it behaviorial.

My Yoshi is a pee-boy and he is on "kitty porzac". It is not very expensive, it is like $12.00 and it lasts 3 1/2 months - and well worth every cent of it!! But, he is on it for life but this is a very small price to pay to keep everyone healthy & happy in this house. Talk with you vet about medications, there are several different types, so your vet will know the best one for Allen.

Good luck & hang in there! I know how frustrating this is, but don't give up on them. This is there only way of expressing their frustration to us!